Grain boundary processes, during the plastic deformation of bicrystals, were studied by means of transmission electron microscopy; using 2 methods. These were in situ straining in the electron microscope followed by post mortem examination, and the post mortem observation of specimens which had previously been deformed by in situ synchrotron radiation X-ray topography. Two mechanisms were identified which governed slip propagation across a coherent twin boundary in an Fe-Si alloy bicrystal. The first mechanism was the dissociation of a slip dislocation, with its Burgers vector lying parallel to the boundary, into 3 equal grain-boundary dislocations. The second mechanism was the decomposition of a slip dislocation, with its Burgers vector inclined to the boundary, into a dislocation which was mobile in the other grain; plus 2 screw grain-boundary dislocations.

Transformation of Slip Dislocations in Σ3 Grain Boundary. J.Gemperlová, A.Jacques, A.Gemperle, N.Zárubová: Interface Science, 2002, 10[1], 51-7